In the field of body exercise and strength training, there is a need to exercise the posterior deltoid rotator cuff, rhomboideus, latissimus dorsi, and trapezius muscles under a resistive load. Various exercisers have been devised to strengthen these muscles of the body through pulling movements, including pulling weight-bearing cables over pulleys or using a complicated lever apparatus with each arm bearing a separate load. However, the use of available exercise machinery does not vary the resistance presented to the muscles as the body's ability to overcome resistance increases. The known devices fail to vary the load between stages in the exercise when the body is weaker such as when the elbows are fully flexed and they fail to promote proper joint alignment as the exercise is performed. A need exists for an exercise machine which can be safely used to effectively resist the action of the back muscles and which provides variable loading and proper joint alignment as the device is used.